This article reports research into the nature and functioning of school governing bodies in different socio-economic and performance contexts. The research analysed 5000 responses from a national questionnaire-based survey and undertook 30 case studies of school governing. The research confirmed that school governing in England is a complex and onerous responsibility that places governing bodies under considerable pressure. The socio-economic and performance contexts can be particularly demanding additional pressures. Governing bodies interact with those contexts in a complex way which we explain using the notions of governance capital and governance agency. Governance capital is the network of individuals and their capabilities, relationships and motivations that are available for the governing of a school. It is likely to be greater for schools that: are well regarded; are in high socio-economic status settings; and have high levels of pupil attainment. These effects may add and mutually reinforce creating an "amplifier effect", which may significantly impact on the governing of a school. Governance agency is the capacity of those involved in the governing of a school to act. It is significant; can ameliorate the effects of low governance capital; and complicates the relationship between governing, performance and socio-economic context. (Contains 2 tables.)